Method of and mechanism for constructing electric conduits and armoring flexible tubes and electric cables.



No. 630,503. Patented Aug. 8, I899.

E. T. GREENHELD.

METHOD OF AND MECHANISM FOR CDNSTBUCTINGELECTNIC CONDUITS AND ABMORING FLEXIBLE TUBES AND ELECTRIC GABLES.

(Application filed Mar. 29, 1899.)

(No Model.)

UNITED STATES PATENT OFFICE} ED WVIN T. GREENFIELD, OF NEW YORK, N. Y.

METHOD OF AND MECHANISM FOR CONSTRUCTING ELECTRIC CONDUITS AND ARMORING FLEXIBLE TUBES AND ELECTRIC CABLES.

SPECIFICATION forming part of Letters Patent l\To. 630,503, dated August 8, 1899.

Original application filed December 15, 1898, Serial No. 699,327. Divided and this application filed March 29, 1899. Serial No. 710,920. (No model.)

To all whom it may concern.-

Be itknown that I, EDWIN T. GREENFIELD, acitizen of the United States, residing at New York, in the borough of. Manhattan, county and State of New York, have made a new and useful Invention in Methods of and Mechanism for Constructing Electric Conduits and Armoring Flexible Tubes and Electric Cables, of which the following is a specification.

My invention relates particularly to the ar moring of flexible electric conduits, insulated electric cables, flexible hose-pipes, and. flexible tubes in general, and the present application is a division of an application filed by me in the United. States Patent Office on the 15th day of December, 1898, bearing Serial N 0. 699,327, in which application I have described and claimed in detail mechanism for armoring flexible electric conduits, pipes, or tubes and insulated electric cables, the present application being directed broadly to the method of effecting such armoring and also to mechanism for effecting a similar armor ing with the aidof a single strip of metal, the mechanism described intheabove-mentioned application being adapted to armor a conduit or cable with two interlocking strips of metal by forcing the same through a forming or bending die and giving to them an interlocking spiral relation about the conduit, tube, or cable.

My invention will befully understood by referring to the accompanying drawings, in which- Figure 1 illustrates in perspective view the mechanism for and method of armoring a flexible conduit, tube, or hose by forcing a single strip of metal around the same in successive spiral convolutions, the forming or bending die being openfor the purpose of showing the interior structure thereof, the trough which guides the metal armoring-strip being partly broken away for the purpose of showing the interior of the structure thereof. Fig. 2 is a detail elevational view of the feedrolls illustrated in Fig. 1 as seen looking at the same from the left toward the right-hand end of the drawings, the metallic strip between said feed-rolls being shown in sectional View. Fig. 3 is a perspective view illustrating the essential parts necessary to effect the armoring of an electric cable or conduit by my novel method of operation when two metallic strips are used and caused to surround the cable with an interlocking spirally-wound armor, this form of the apparatus being identically like that disclosed in the above-mentioned application for armoring cables and conduits in the manner and by the means therein described. Fig. 4 is a detail eleva :tionalview of the inner set of rolls illustrated 'in Fig. 3 as seen looking at the same from the left toward the right-hand end of the drawings, the metallic strip between said feed-rolls being shown in sectio nal view.

Referring now to the drawings in detail and first to Fig. 1, M represents a two-part hollow forming or bending die having a cylindrical bore and screwthreaded interiorly,

said screw-threads having the necessary pitch to cause the metal strip when forced forward therein to assume successive spiral convolu- -tions' around the tube to be armored.

same manner as disclosed in my above-named application.

J represents a trough secured also to the same frame or support which sustains the die M, said trough being provided with a guideway between it and a cover or lid L. This guideway is so located in the trough J that it presents the armoring-strip e to the screwthreadedportion of the forming or bending die M through an opening M in said die at the proper angle. (See Fig. 3.)

K K are feed-rolls located with their tangential surfaces in' alinement with the guideway in the trough J and supported by shafting S S, geared to a source of power in the same manner as disclosed in my priorapplication above referred to, the function of said feedrolls being to force the metal strip forward into the die.

In Fig. l of the drawings the working surface of the roller K is concave and the corresponding working surface of the roller K is convex, so as to give to the strip 6 a curvilinear shape.

If is a tongue constituting a part of the cover or lid L and adapted to fit into the upper portion of the opening M, so as to preserve the continuity of the guideway to the inner surface of the forming or bending die.

The operation of this form of the apparatus for constructing a metallic tube A or armoring a flexible tube A is as follows: The two parts of the forming or bending die M are of course secured together, so that they constitute one continuous screw-threaded forming or bending die. The tube or cable A is inserted from the left, with its inner end directly opposite the inner end of the guideway. The thin flat metal strip e is now inserted between the two feed-rolls K K, which are rotated in the proper direction to cause the same to force said strip forward through the guideway under the tongue t and against the inner surface of the forming or bending die M, thereby causing it to be continuously forced forward and wound around the tube A, and as the metal is thus continuously forced forward the action of the screw-threads is such as to form of said strip about the tube A an armor A of successive spirals or convolutions with their adjacent edges in substantial alinement. The action of the strip 6 as thus driven forward tends always to r0 tate the tube A, the spiral action of the die being such as to simultaneously advance the tube A and its surrounding armor.

WVith such an apparatus definite lengths of tubing can of course be armored. Should it be required to manufacture more extended lengths, the appliances disclosed in my before-mentioned application may be added in such manner as to make a completed machine for that purpose.

In the modified form shown in Fig. 3 there are two sets of feed-rolls K K K K supported by shafting S S S 8, two guideways, one for each set of feed-rolls, and two lateral openings M M in the side of the forming or bending die M, and screw-threads m m, respectively concave and convex, for the purpose of receiving the concave and convex metal strips 6 e, to which such concavity and convexity are given by the sets of forming and feeding rolls K K I K, the rollers K K having concave and the rollers K K convex working surfaces. One of each of these feedrolls is provided with teeth if t for giving to the inner and outer surfaces of the respective strips indentations Z, in order to enable the same to be more easily formed or bent around the cable A. lVith this form of the apparatus the cable A, having internal conductors w w, is armored by forcing the two metallic strips forward into the forming or bending die, the strip (2 being forced spirally around the same, with its concave surface outward, and the strip 6' similarly wound around the first-named convolutions, with its convex side outward,so as to form a continuous armor of interlocking spirals a a, the cable A and its surrounding armor being continuously rotated and advanced to the right by the action of the screw-threaded die. All of the parts of this form of the apparatus illustrated in Fig. 3 are substantially the same as the like parts disclosed in the before-mentioned application, and no claiunis made in the present application to mechanism adapted to armor a cable or conduit with two or more interlocking metal strips wound spirally therearound, as this feature constitutes in part the subject-matter of claims in the before-mentioned application, the same being illustrated here forthe purpose of embodying in the present application method claims of the nature hereinafter embraced.

I do not limit myself to the especial forms of mechanism herein illustrated in Figs. 1 and 3 of the drawings for the purpose of practicing the methods attributable to such structures. I believe I am broadly entitled to claim a method of armoring or surrounding flexible tubing-such as electric conduits, flexible hose, and the likcby forcing one or more strips of flexible material, such as metal, continuously forward against a bending-surface in such manner as to cause said strip or strips to assume spiral convolutions therearound, and my claims are generic as to such method of operation without relation to any special form of mechanism for effecting such result. It is also obvious that this method of operation and means for effecting the same may be utilized for the construction of flexible tubing, such as armored conduits,without any interior flexible tube, and I contemplate the practice of such method and the use of such mechanism for that purpose as well.

Having thus described my invention, what I claim, and desire to secure by Letters Patent of the United States, is-- 1. The described method of forming a tube of flexible material such as metal, consisting in causing the material to be forced continuously forward against a bending surface which causes it to be formed into successive spirals with their lateral edges adjacent to each other and in substantial alinement.

2. The described method of forming a tube of flexible material such as metal, consisting in forcing the material'continuously forward against a bending-surface which gives to it successive spiral convolutions and in simultaneously advancing the completed tube by such forcing action.

3. Mechanism for forming flexible tubes from a single strip of metal, consisting of a die having a screw-threaded interior surface, in combination with a guideway operatively connected with said screw-threaded surface and means for forcing said strip continuously forward, substantially as described.

4. Mechanism for forming flexible tubes from a single strip of metal, consisting of a hollow screw-threaded die having a lateral opening operatively connected therewith, in combination with a guideway and feed-rolls for guiding and advancing said strip of metal continuously forward and forming it into a tube of spiral conformation, the lateral edges of the strip when it assumes a tubular form being located in substantial alinement with each other, substantially as described.

5. A hollow screw-threaded die for forming a strip of metal into a flexible tube, said die having a lateral opening operatively connected with the screw-threaded portion there of, and adapted to receive continuouslythe strip from which the tube is to be composed, substantially as described.

6. A hollow screw-threaded die for forming V a strip of metal into a flexible tube, said die having a lateral openingextending from without to within the interior thereof and at an angle substantially that of the pitch of the screw-threads, substantially as shown and described.

7 A die for constructing tubing from a strip of metal composed of two parts, screwthreaded interiorly,and having a lateral opening adapted to receive the strip of metal from which the tube is to be constructed, substantially as described.

In testimony whereof I have hereunto subscribed my name this 27th day of March, 1899. 30

EDWIN T. GREENFIELD. Witnesses:

O. J. KINTNER, M. F. KEATING. 

